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Cardiopulmonary arrest during pregnancy is a devastating event necessitating rapid intervention from experienced practitioners to reduce the incidence and severity of adverse maternal and fetal outcomes. Perimortem cesarean delivery is rarely performed within the recommended time frame to meet these goals. We describe a case of a successful perimortem cesarean delivery after the “4-minute rule” in a morbidly obese parturient with goiter and preeclampsia.

From the Department of Anesthesiology, North Shore/LIJ Health System, New Hyde Park, New York.

Perimortem cesarean delivery is defined as a cesarean delivery initiated after cardiopulmonary resuscitation (CPR) has been initiated. Cardiopulmonary arrest during pregnancy is a rare event, estimated to occur in approximately 1:20,000 to 1:50,000 parturients in all stages of pregnancy.1 Mhyre et al.2 recently estimated the incidence of cardiac arrest in women hospitalized for delivery in the United States to be 1:12,000. This increased frequency of cardiac arrest may indicate that delivery and postpartum are high-risk periods for this event.1 The etiology of maternal cardiac arrest may be unique to pregnancy, due to a preexisting condition or a combination of events related to both. Pregnancy has long been considered a goiterogenic stimulus, and thyroid volume may increase by as much as 30%.3 The incidence of goiter in pregnant women varies worldwide and is more prevalent in geographic areas of iodine deficiency. Data suggest that parturients with preexisting diffuse goiter are at greater risk for further gland enlargement than their nonpregnant counterparts.4 Here, we present a case of cardiopulmonary arrest and perimortem cesarean delivery followed by complete recovery of both mother and fetus in a morbidly obese female with chronic hypertension, superimposed preeclampsia, and goiter.

Multiple attempts to contact the patient were unsuccessful, and the patient was lost to medical follow-up. The Feinstein Institute IRB approved publication of this case report, without patient consent.

CASE DESCRIPTION

A 38-year-old, 292-lb (131 kg), G7P3 female with a medical history significant for longstanding chronic hypertension and nontoxic goiter for many years was sent from the obstetric clinic to the hospital at 35 weeks’ gestation for uncontrolled hypertension and a headache. The patient’s obstetric history was significant for 1 previous pregnancy complicated by preeclampsia resulting in cesarean delivery at 36 weeks’ gestation. Her prepregnancy weight was reported to be 250 lb. A presumptive diagnosis of preeclampsia without proteinuria was made on this admission based on the extent of the increase of her arterial blood pressure that had been previously well controlled with labetalol. She was not taking other medications and denied use of alcohol or drugs. Her vital signs on admission to the labor and delivery suite were arterial blood pressure 199/102 mm Hg, heart rate 104 per minute, respirations 18 per minute, and oxyhemoglobin saturation of 100% while breathing room air. Breath sounds were clear on auscultation bilaterally. Fetal monitoring revealed a baseline heart rate of 155 per minute, with moderate variability and no decelerations. Her physical examination was notable for a swollen left calf and an enlarged thyroid with tracheal deviation. On questioning, the patient informed the anesthesia team that her thyroid “pushes” on her trachea and that she had had multiple sporadic episodes of shortness of breath throughout her pregnancy. She insisted on remaining upright throughout the physical examination and refused oxygen therapy via nonrebreathing mask, claiming that it “bothered” her. Her respiratory rate was now noted to be 24 per minute, and lung fields remained clear to auscultation. Her airway was classified as a Mallampati 3, with a thyromental distance >6 cm and adequate mouth opening. Labetalol 20 mg IV and hydralazine 10 mg IV were given for blood pressure control. An initial IV loading dose of magnesium sulfate 4 g over 20 minutes followed by infusion at 2 g/h was administered for prophylaxis against eclampsia. The patient’s oxyhemoglobin saturation remained between 99% and 100% with oxygen delivered via nasal cannula at 3 L/min. Attempts to place her in the semirecumbent position to perform a chest radiograph resulted in extreme agitation with worsening tachypnea and a precipitous decrease in her SpO2 to 77%. The decision was made to rush her to the operating room for urgent cesarean delivery, and the magnesium sulfate infusion was discontinued. During transport while upright she became unresponsive, apneic, and pulseless. Chest compressions were begun, and epinephrine 1 mg IV followed by vasopressin 40 U IV were administered in the operating room without apparent effect. The electrocardiogram revealed pulseless electrical activity. A wedge was placed under the right buttock in an attempt to relieve aortocaval compression. Mask ventilation was difficult, and an unsuccessful attempt at oral tracheal intubation was made using the GlideScope® videolaryngoscope (Verathon Medical, Bothell, WA). Pink, frothy secretions were noted in the larynx and the vocal cords could not be visualized. A size 4 i-gel™ laryngeal mask airway (Intersurgical Ltd, Wokingham, Berkshire, UK) was inserted and ventilation continued successfully, evidenced by low but detectable end-tidal CO2. Increased airway pressure secondary to pulmonary secretions and suspected tracheal compression were noted. SpO2 signal strength was poor, probably reflecting the patient’s decreased cardiac output during CPR. A decision to proceed with cesarean delivery was made based on evidence that delivery of the fetus within 5 minutes of a cardiac arrest may improve both fetal and maternal outcomes. A “dirty” cesarean delivery was performed on the hospital bed approximately 5 minutes after cardiopulmonary arrest was diagnosed while chest compressions continued. Shortly after delivery of a live fetus, the patient’s blood pressure and heart rate returned, and a successful blind oral tracheal intubation with a styletted 6.5 cuffed endotracheal tube was performed using a #4 Macintosh blade. The infant’s Apgar scores were 3, 6, and 9 at 1, 5, and 10 minutes, respectively. An arterial blood gas drawn 10 minutes after return of spontaneous circulation demonstrated adequate oxygenation along with a severe mixed respiratory and metabolic acidosis that corrected with adequate ventilation and tissue perfusion. Umbilical cord blood gas measurements reflected maternal arterial blood gas findings, and the infant was briefly treated with nasal continuous positive airway pressure. Intraoperative transesophageal echocardiography demonstrated a hyperdynamic left ventricle with concentric remodeling. Right ventricular size and function were normal, and no thrombus was visualized in the right heart or main pulmonary artery. Anesthesia was maintained with 0.5 minimum alveolar concentration sevoflurane in 100% oxygen, rocuronium 50 mg, and fentanyl 250 mcg for the remainder of the procedure. She was brought to the intensive care unit tracheally intubated and in stable condition receiving a propofol infusion administered at 50 mcg/kg/min. A postoperative chest roentgenogram demonstrated diffuse pulmonary congestion suggestive of pulmonary edema. A computerized tomography scan of the patient’s neck obtained concurrently demonstrated a thyroid lobe nodule measuring 8.2 × 5.2 × 4.2 cm (Fig. 1), which had markedly increased in size since a previous study done 8 weeks earlier. The patient’s magnesium level was 3.2 mg/dL, and a CT pulmonary angiography did not demonstrate any emboli. Initial treatment in the intensive care unit included continued sedation, IV steroids, and multiple antihypertensive drugs for resistant high blood pressure. A thyroid-stimulating hormone level of 13.46 µIU/mL indicated new-onset subclinical hypothyroidism that was treated with synthroid. Numerous attempts to separate the patient from mechanical ventilation failed because of agitation and severe hypertension when sedation was withheld. She “self-extubated” her trachea on postoperative day (POD) 8 and was successfully treated with racemic epinephrine for postextubation stridor. Subsequently, her blood pressure and mental status dramatically improved. Although she was alert and oriented × 3, she had mild retrograde amnesia and trouble following lateralizing multistep commands. She was discharged from the hospital to a rehabilitation facility on POD 15 and ultimately made a full recovery. Her infant was discharged home on POD 8 with no apparent sequelae resulting from this event.

DISCUSSION

In 1982, Gertie Marx reported 5 cases of cardiac arrest during induction of anesthesia for elective cesarean delivery.5 CPR lasting more than 10 minutes was performed in all 5 cases, but in only 3 patients was delivery of the fetus accomplished expeditiously. These 3 patients survived, 2 without serious sequelae. Delivery was delayed in the remaining 2 parturients, and both sustained permanent brain damage. Published case reports since that time described the difficulties in resucitating women in the third trimester and the importance of immediate delivery of the fetus to prevent catastrophic, hypoxic brain injury in the mother.6,7 These reports spawned the “4-minute rule,” which recommends initiating surgical delivery of the fetus within 4 minutes of maternal cardiac arrest and delivery within 5 minutes to reduce the likelihood and severity of maternal and fetal adverse events.7

Acute airway obstruction secondary to an enlarged thyroid as the cause of cardiopulmonary arrest during pregnancy has only recently been reported.8 In case reports describing upper airway obstruction in parturients with a goiter,9–11 3 patients in the third trimester safely underwent elective cesarean delivery followed by an immediate thyroidectomy, 2 required urgent cesarean delivery secondary to deteriorating fetal status, and 1 patient in her second trimester of pregnancy had an urgent thyroidectomy after developing severe airway obstruction.

We believe critical narrowing of the trachea, resulting in airway obstruction and negative pressure pulmonary edema from enlargement of the goiter during pregnancy, was a major contributor to this patient’s acute airway compromise and subsequent cardiac arrest. There was no evidence of pulmonary emboli on a CT angiogram, and a serum magnesium level, drawn 40 minutes after the magnesium infusion was stopped, was subtherapeutic, suggesting that magnesium overdose was not a precipitating factor. Although she had a longstanding history of nontoxic goiter, she visited the ear-nose-throat clinic in her second trimester complaining of increased thyroid size accompanied by sporadic episodes of shortness of breath. During this visit, she reported having had a CT scan of her thyroid in 2000, which demonstrated tracheal compression. She was scheduled for a thyroid sonogram and advised to have her thyroid removed postpartum. The recent increased thyroid-stimulating hormone level during this pregnancy may have contributed to a significant increase in thyroid size. Previous thyroid function tests were within normal limits. Mucosal engorgement causes a decrease in tracheal diameter during pregnancy, a change that can be exaggerated in preeclampsia. Women with preeclampsia may also have pharyngolaryngeal and subglottic edema causing distortion and obstruction of the airway. Resolution of these conditions may explain why tracheal extubation was successful in this case. Postoperatively, transient thrombocytopenia to less than 100,000 K/μL supported the diagnosis of preeclampsia in this patient.

Thyroid surgery during pregnancy is controversial. A retrospective cross-sectional analysis by Kuy et al.12 revealed pregnant women undergoing thyroid or parathyroid surgery have worse clinical outcomes compared with their nonpregnant counterparts. Complications such as early labor and fetal death occurred in 5.5% of pregnancies. Cesarean delivery, hysterectomy, and dilatation and curettage occurred in 4.5% of cases. The authors concluded only symptomatic parturients or those with advanced and poorly differentiated thyroid carcinoma should be considered for surgery. This recommendation conflicts with other studies finding no maternal or fetal complications when thyroid surgery was performed during pregnancy.13,14 This case demonstrates how rapidly respiratory decompensation can occur when goiter is accompanied by comorbid conditions that may further compromise lung function. Our patient was morbidly obese, with chronic hypertension and superimposed preeclampsia, disease states that may be associated with respiratory compromise. Pulmonary edema occurs in approximately 3% of women with preeclampsia, with 30% of those cases occurring postpartum.15

This case supports consideration of an elective second trimester thyroidectomy or thyroid lobectomy in selected patients, particularly for those who are morbidly obese and have other comorbidities that place them at risk for respiratory compromise as the pregnancy advances. However, a decision to subject both mother and fetus to surgery and anesthesia in the second trimester must be individualized and weighed against the benefit of avoiding a potential catastrophic event in the later stages of pregnancy.